Disc brake and wheel assembly

ABSTRACT

A disc brake and wheel assembly in which an annular brake disc has axially extending circumferentially spaced lands and grooves formed on its outer peripheral surface, and a brake disc support and drive member, provided as part of the wheel assembly, has a bell-like configuration, the generally radially extending portion of the member being mounted on the wheel assembly hub and the generally cylindrical portion of the member having circumferentially spaced projections received in the disc grooves and engaging the edges of the disc lands in rotary driving and axially relatively movable relation so that the disc is rotatably driven with the wheel assembly and is axially movable in relation thereto for brake adjustment. The brake caliper is of the fixed type, with one axially movable brake shoe and one fixed brake shoe arranged to frictionally engage opposite sides of the brake disc when actuated. A piston and cylinder arrangement in one side of the caliper housing is provided to move the movable brake shoe. It may also have a manually actuated mechanism so that the brake can also function as a parking brake, and may be provided with an automatic adjusting mechanism.

United States Patent [19] Brooks et a1.

DISC BRAKE AND WHEEL ASSEMBLY [75] Inventors: Frank W. Brooks; Thomas D.

Naismith, both of Dayton, Ohio [73] Assignee: General MotorsCorporation,

Detroit, Mich.

[22] Filed: July 14, 1972 [21] Appl. No.: 271,660

[52] US. Cl 188/18 A, 188/71.1, 188/71.8, 188/73.5, 192/7017, 192/7019[51] Int. Cl B60t 1/06 [.58] Field of Search ,188/18 A, 71.1, 71.5,73.5,

[56] References Cited UNITED STATES PATENTS 1,172,146 2/1916 Loomisl92/70.2 1,415,841 5/1922 Seitz 192/702 3,404,756 10/1968 Swift l88/72.63,478,844 11/1969 Beuchle 188/18 A 3,586,132 6/1971 Tantlinger 188/18 A3,630,320 12/1971 Lochmann 188/18 A FOREIGN PATENTS OR APPLICATIONS1,073,362 3/1954 France 188/18 A Primary Examiner-George E. A. HalvosaAttorney, Agent, or Firm-D. D. McGraw Jan. 29, 1974 [57] ABSTRACT Iatively movable relation so that the disc is rotatably driven with thewheel assembly and is axially movable in relation thereto for brakeadjustment. The brake caliper is of the fixed type, with one axiallymovable brake shoe and one fixed brake shoe-arranged to frictionallyengage opposite sides of the brake disc when actuated. A piston andcylinder arrangement in one side of the caliper housing is provided tomove the movable brake shoe. It may also have a manually actuatedmechanism so that the brake can also function as a parking brake, andmay be provided with an automatic adjusting mechanism.

1 Claim, 4 Drawing Figures PATENTED M 2 9 3974 SHEET 2 OF 2 DISC BRAKEAND WHEEL ASSEMBLY The invention relates to an assembly including a discbrake and wheel and, more particularly, to one having a movable disc andfixed caliper, the disc being supported and driven by a part of thewheel assembly.

In the preferred embodiments illustrated and described herein, the discis annular with splines on its outer periphery interconnecting inrotative driving relation for axial sliding relation with a brake discsupport and drive member. Axial sliding movement of the .disc permitscompensation for brake lining wear. The caliper is open at its radiallyoutward side to receive the disc, the caliper housing extending throughthe annular opening of the disc adjacent the disc inner periphery toprovide for mounting and actuation of brake pad assemblies on oppositesides of the .disc. The caliper is preferably formed as a part of asteering knuckle if the assembly relates to a steering wheel, or as partof a fixed bearing housing structure if it relates to a nonsteeringwheel. A parking brake and shoe adjusting mechanism may be provided. Thebrake disc support and drive member may either be integrated with thewheel disc in the area in which the wheel disc is attached to the wheelrim, or may be a separate wheel assembly member attached to the wheelhub and providing means for engaging the disc splined periphery indriving and sliding relation. The constructions are particularly adaptedto easy brake pad assembly replacement, it only being necessary to usethe conventional wheel lug wrench to move the wheel assembly, includingthe brake disc support and drive member, in order to have ready accessto the removable brake pad assemblies.

IN THE DRAWINGS F IG. 1 is a cross-section view, with parts broken away,showing a wheel and brake assembly embodying the invention.

FIG. 2 is a fragmentary cross-section viewof the assembly of FIG. 1,taken in the direction of arrows 22 of that FIGURE.

FIG. 3 is a cross-section view of a modification of the assembly of FIG.1, and is generally similar to that FIG- URE.

FIG. 4 is a fragmentary cross-section view of the assembly of FIG. 3taken in the direction of arrows 44 of that FIGURE.

The wheel and brake assembly of FIGS. 1 and 2 is illustrated as being apart of a steerable, driving wheel arrangement such as is used on frontwheel drive vehicles. However, the assembly is readily adapted tonon-steering wheels or non-driving wheels, or wheels which are neitherdriven nor steered. The assembly 10 includes a wheel assembly 12 and adisc brake assembly 14. The wheel assembly 12 has a hub 16 provided withan axle 18 mounted in suitable bearings 20 and 22. The bearings arereceived in a non-rotatable bearing housing 24 which, in the particularassembly illustrated, is also a part of the steering knuckle 26. Asuitable drive for the wheel assembly 12 is provided by means of shaft28 and a universal joint 30, suitably connected to stub axle 18 so as topermit steering and driving of the wheel assembly. The wheel assemblyalso includes a wheel disc 32 and a wheel rim 34. The wheel disc 32 hasgenerally radially extending first section 36 mounted by suitable boltsand nuts 38 to the wheel hub 16, and a generally cylindrical secondsection 40 integrally formed with the first section 36 and presentingtherewith a somewhat bell-like configuration. The wheel rim 34, on whichis mounted a' tire, not shown, is secured in a suitable manner, such aswelding, to the wheel disc second section 40. The outer end of the wheeldisc second section 40 is formed to provide a circumferentiallyextending series of radially inwardly facing lands 42 and grooves 44 inalternating relation. Since the wheel disc 32 is illustrated as beingformed of sheet metal, it is readily apparent that provision of theinwardly extending lands 42 results in radially corresponding outwardlyfacing grooves 46, and the provision of the radially inwardly formedgrooves 44 results in radially corresponding outwardly extending lands48. Therefore, the lands 48, which form the outer sides of grooves 44,are the portions of the Wheel disc second section 40 to which the wheelrim 34 is attached. The lands and grooves 42, 44, 46 and 48 extendparallel to the axis 50 about which the wheel assembly rot-ates. Theinwardly extending lands 42 are defined by sides or shoulders 52, whichalso are axially parallel to the wheel assembly axis 50.

The disc brake assembly 14 includes a caliper assembly 54 and arotatable brake disc 56. The caliper assembly further includes a housing58, integrally formed with the bearing housing 24 and steering knuckle26 to provide caliper legs 60 and 62 positioned on opposite sides ofdisc 56 and arranged to mount oppositely acting brake pad assemblies 64and 66 so that the brake pad assembly linings 68 and 70 are engageablewith the disc opposite friction surfaces 72 and 74, respectively. Thebrake pad assembly 64 is suitably mounted on caliper leg 60, and thebrake pad assembly 70 is suitably mounted on the caliper leg 62 so as tobe engaged by the brake actuating piston 76, which is movable in thebrake cylinder 78 formed in caliper housing leg 62, when pressurizedbrake fluid is provided in the pressure chamber 80. The brake disc 56has splines 82 formed on its outer periphery as lands 84 and grooves 86arranged in alternating circumferentially spaced relation. Lands 84 havesides or shoulders 88 which extend axially parallel to the axis-50 andare complementary to the shoulders 52 of lands 42 so as to engage thoseshoulders in rotative driving relation while permitting axially slidingmovement of the brake disc 56 relative to the brake disc support anddrive member embodied in the wheel disc 32.

Since the caliper is fixed against axial movement, the brake padassembly 64 cannot move as the brake lining wears. Therefore, the brakedisc 56 is permitted to move axially so that when the brake pad assembly66 is actuated against the friction surface 74, the brake disc moves tofrictionally engage the brake lining 68. As the linings wear, brake disc56 will move further and further toward caliper leg 60 so as to maintainbrake adjustment. Although not shown in FIG. 1, a suitable brakeadjusting mechanism may be provided in a manner similar to that of FIG.3. Brake adjustment may also be provided due to action of the pistonseal 90 as the piston 76 moves outwardly in cylinder 78, in a mannerwell known in the art.

The wheel and brake assembly of FIGS. 3 and 4 is illustrated as beingpart of a steerable wheel. The assembly 110 includes a wheel assembly112 and a disc brake assembly 114. The wheel assembly 112 has a hub l 16which is mounted to rotate in suitable bearings and 122. The bearingsare received in a non-rotatable bearing housing 124 which is also a partof the steering knuckle 126. The wheel assembly also includes a brakedisc support and drive member 128, a wheel disc 132, and a wheel rim 134on which a tire, not shown, is conventionally mounted. The wheel rim issuitably secured to the wheel disc by welding or other appropriatemeans. The wheel disc 132 has a generally radially extending firstsection 136 mounted by suitable bolts and nuts 138 to the wheel hub 116and a generally cylindrical second section 140 integrally formed withthe first section 136 and presenting therewith a somewhat belllikeconfiguration. The outer end of the members second section 140 is formedto provide a circumferentially repeated series of axially extendingfingers or tabs, the tabs being preferably provided in sets of three,each set 142 having a pair of outer tabs or fingers 144 and anintermediate tab or finger 146. Each set of tabs or fingers ispositioned in circumferentially spaced relation to the adjacent set. Thetabs or fingers are formed as cantilever springs and extend generallyparallel to the axis of rotation of the hub 116 with their outer endsbeing bent slightly outward to have a camming action for ease of brakedisc installation. They have sides or edges so arranged that the sides148 and 150 of each intermediate finger engaged the immediately adjacentsides 152 of the outer fingers 144 in friction damping relation. Also,each intermediate finger 146 is offset radially relative to the twoouter fingers 144 of each set 142 so that the fingers are not in anyexact circumferential alignment, the circumferential surfaces of theintermediate fingers being radially spaced from the comparablecircumferential surfaces of their adjacent outer fingers. When the discbrake assembly used includes a brake disc supported on its outerperiphery as disclosed in the drawings, the intermediate finger 146 ofeach set is preferably offset slightly radially inward in relation tothe adjacent outer fingers 144.

The disc brake assembly 114 includes the caliper assembly 154 and arotatable brake disc 156. The caliper assembly further includes ahousing 158 which is integrally formed with the bearing housing 124 andthe steering knuckle 126 to provide caliper legs 160 and 162 positionedon opposite sides of brake disc 156. The caliper legs are arranged tomount oppositely acting brake pad assemblies 164 and 166 so that thebrake pad assembly linings 168 and 170 are engageable with the brakedisc opposite friction surfaces 172 and 174, respectively=The brake padassembly 164 is suitably mounted on caliper leg 160, and the brake padassembly 170 is suitably mounted on the caliper leg 162'so as to beengaged by the brake actuating piston 176. Piston 176 is movable in thebrake cylinder 178 which is mounted in the caliper housing leg 162.Piston 176 is moved to actuate the brake when pressurized brake fluid isprovided in the pressure chamber 180. A piston adjusting mechanism 182and a mechanically actuated brake system, including the ball and ramparrangement 184, pin 186, and lever 188, are also provided. The manuallyactuated mechanism operates in the manner disclosed in US. applicationSer. No. 195,285, filed Nov. 3, .197! now US. Pat. No. 3,724,605 issuedApr. 3, 1973, entitled Disc Brake With Integral Parking Brake," andassigned to the common assignee. It provides for axial movement of thepin 186 toward the brake disc 156 when lever 188 is rotated, the end ofthe pin operatively moving the brake pad assembly 166 into brakingengagement with the brake disc. The adjusting mechanism 182 permits onlylimited retraction of the piston 176 upon hydraulic brake release so asto maintain the brake in adjustment at all times. Since the specificoperation of the adjusting mechanism need not be described in detailherein, reference is made to the above-noted patent application forfurther details. Other known types of adjusting mechanisms and manuallyactuated mechanisms may also be utilized, those illustrated herein beingmerely by way of example.

The brake disc 156 has splines 192 formed on its outer periphery aslands 194 and grooves 196 arranged in alternating circumferentiallyspaced relation. Lands 194 have sides or shoulders 198 which extendaxially parallel to the axis of rotation of the disc and arecomplementary to the outer sides or shoulders 200 of the outer tabs orfingers 144 so as toengage those shoulders in rotative driving relationwhile permitting axially sliding movement of the brake disc 156 relativeto the brake disc support and drive member 128. The brake disc grooves196 have bottom surfaces 202 which are forcibly engaged by the innercircumferentially extending surface 204 of each intermediate finger 146.These fingers act against the brake disc to prevent the disc fromrattling, and are assisted by the friction damping action between edgesof the intermediate and outer fingers and the outer fingers and thebrake disc lands. Similarly, other brake noises tend to be damped out.

Since the brake caliper is fixed against axial movement, the brake disc156 is permitted to move axially on finger sets 142 as the brake liningswear and the brakes are actuated, thus permitting the maintenance ofbrake adjustment. When the brake pad assemblies require replacement, thewheel assembly is removed and the brake ,pad assemblies may be readilyremoved and replaced without special tools.

What is claimed is:

1. A disc brake and wheel assembly comprising:

an annular brake disc having opposed annular friction surfaces and aperipheral surface, axially extending circumferentially spaced lands andgrooves formed on saidperipheral surface in alternating arrangement;

means selectively frictionally engaging said disc friction surfaces; and

a wheel assembly having a hub and a rim and a brake disc support anddrive member, said member having a generally radially extending firstsection mounted on .said hub and a generally cylindrical second sectionintegrally formed with said first section, said member second sectionhaving circumferentially spaced projections received in said discgrooves and engaging the edges of said disc lands in rotary driving andaxially relatively movable relation whereby said disc is rotatablydriven with said wheel assembly and axially movable in relation theretofor brake adjustment,

said wheel assembly further having a wheel disc section axially adjacentsaid brake disc support and drive member and secured to said hub andsaid rim, said brake disc support and drive member being radially inwardof and spaced from said rim, said brake disc support and drive memberprojections being axially extending fingers, each of said brake discgrooves receiving a set of three of said axially extending fingers, eachset of three fingers having the edges of the intermediate fingerengaging the 6 of each set forcibly engaging the bottom of the brakedisc groove, said friction damping relations existing in the brakereleased and actuated conditions.

1. A disc brake and wheel assembly comprising: an annular brake dischaving opposed annular friction surfaces and a peripheral surface,axially extending circumferentially spaced lands and grooves formed onsaid peripheral surface in alternating arrangement; means selectivelyfrictionally engaging said disc friction surfaces; and a wheel assemblyhaving a hub and a rim and a brake disc support and drive member, saidmember having a generally radially extending first section mounted onsaid hub and a generally cylindrical second section integrally formedwith said first section, said member second section havingcircumferentially spaced projections received in said disc grooves andengaging the edges of said disc lands in rotary driving and axiallyrelatively movable relation whereby said disc is rotatably driven withsaid wheel assembly and axially movable in relation thereto for brakeadjustment, said wheel assembly further having a wheel disc sectionaxially adjacent said brake disc support and drive member and secured tosaid hub and said rim, said brake disc support and drive member beingradially inward of and spaced from said rim, said brake disc support anddrive member projections being axially extending fingers, each of saidbrake disc grooves receiving a set of three of said axially extendingfingers, each set of three fingers having the edges of the intermediatefinger engaging the adjacent edges of the two outer fingers in frictiondamping relation, the intermediate finger being offset radially relativeto the two outer fingers, the other edges of the two outer fingersengaging the adjacent edges of said brake disc lands in friction dampingrelation, at least one of the three fingers of each set forciblyengaging the bottom of the brake disc groove, said friction dampingrelations existing in the brake released and actuated conditions.